An important step in the development of computer systems is testing the IC chips of a particular system to determine if there are "bugs" in the design or implementation. In typical testing schemes, some or all of the pins on the IC chip are connected to leads of test equipment such as a logic analyzer, and then the circuit including the chip(s) under test is operated and observed.
In typical computer systems, the chips are inserted in a permanent socket, which is connected to a system board of the printed circuit variety. During testing, however, a special adapter socket is interposed between the chip under test and the permanent socket. The adapter socket feeds the leads of the the test equipment. The chips under test are thus tested from the component side of the system board because of the relative location of the adapter sockets.
In the test of high speed chips, use of the adapter socket often increases socket lead lengths to a point where power consumption and signal path inductances, and hence noise levels, become unacceptably high. To reduce the noise to an acceptable level, the operating speed must be reduced by lowering the system clock frequency. However, the chips will not have been tested at the actual (higher) operating speeds. As a result, high speed-related bugs may not be detected until later in the implementation of a design, when they are more difficult to remove.